In the proposed investigation we shall continue studies on the mechanism of import and assembly of nuclear coded components of the yeast mitochondrial ATPase complex. These studies will utilize precursor forms of the nuclear coded subunits made in in vitro cell free protein synthesizing systems to characterize the proteolytic processing pathway of assembly and the specific proteolytic enzymes involved. In addition we shall initiate studies to isolate the structural yeast genes for the nuclear coded subunits from E. coli clone banks containing yeast-E. coli plasmid recombinant DNA molecules. These later studies will utilize immunological screening methods with yeast F1 ATPase specific antisera.